Back to the topic and Vixen's question. You don't say if you're playing by ear or learning tunes from a book (or both). If from a book, and the book has the tunes organised by type - jigs, strathspeys, single jigs, slip jigs, etc. - and there's, let's say, three tunes of the same type on a page, why not just play those three tunes as a set. I've tried this myself and it works more often than you might imagine.